There are about 560 operational satellites in the sky. Each one completes an orbit of the Earth approximately every 100 minutes. The cameras and sensors that many of these satellites carry have made satellite imagery pervasive in today’s society. Recreational Internet users zoom in on houses and neighborhoods anywhere in the world. It’s more than entertainment, however. Population research, environmental studies, crisis response planning, inner-city traffic planning, military surveillance and many other applications benefit from the ʺeyes in the skyʺ that remote sensing technology provides.